Matt Prior - Marlborough Downs' "Mr Tree Sparrow" - keeps tabs on another new generation of chicks
During a very hot late afternoon and evening - one of June's record breakers - I watched Matt Prior ring 73 tree sparrow chicks from sixteen broods. A five-hour shift after his day's work.
His conservation work on the Marlborough Downs centres on the tree sparrow, which is on the Red List of endangered birds and was almost extinct in North Wiltshire when he began taking an interest in them.
But he also rings and keeps an eye out for other bird species on the Downs. I watched him ring four cross and noisy three-week old kestrel chicks - and there were hares and barn owls and any number of farmland song birds to see and listen to.
On his evening shift, we seem to have visited most of the 1,086 nestboxes with their specially small (28mm) entrance hole (to keep house sparrows out), in some of the most isolated parts of the Downs - mainly on the Marlborough Downs but also onto the Pewsey Downs.
The best time to ring the chicks is when they are between seven and nine days old - when the fat legs they have when they hatch have grown out and their ankles have formed so the ring stays on.
What really cheered Matt as we drove from colony to colony was that many of the tree sparrow chicks he was handling were in very good shape - showing quite a lot of fat to help them survive after they fledged.
Matt's conservation work with birds is an all-consuming hobby. He has worked for Thames Water for many years - beginning as a junior laboratory technician. He is now a senior process scientist specialising in waste water.
He was introduced to bird watching by his wife Louise and her family. And he only started ringing when he was 28. He is now 46 and reckons that over the years he has ringed twelve thousand tree sparrows.
Tree sparrow pairs have between two and three broods a year - and that makes ringing all the chicks hard work for Matt - checking to see which box has a brood and how soon it will be ready to ring. Ringing helps him trace new populations of the birds and check on their survival as adults.
During the nesting season - which is about sixteen weeks long - he is especially busy: "From early May on I'm out here about 30 to 35 hours a week - through the nesting season. I've turned down trips to Scotland to ring ospreys and golden eagles and to Iceland - I'm not prepared to miss ringing our new generations of tree sparrows - monitoring is so important to provide an evidence base for successful conservation."
During the winter he sometimes takes his skills abroad - combining a holiday with bird work. He has been to Singapore, Canada, Africa - East, South and West, including The Gambia.
Last winter he went under the auspices of an international conservation organisation to Bangladesh - teaching ways to look after and study their birds - and, of course, to ring them.
But his year round work is on the Marlborough Downs: "We still don't fully sort out the adult tree sparrows survival rates - that we're starting to do it." To help with that and to monitor the birds movements around and beyond the downs Matt has a new box of tricks: tracing birds with a Passive Integrated Transponder ('PIT tagging' for short!)
This has a mini reader (like a bar code reader.) Placed in the top of a nesting box, it records the arrival and departure of birds with specially fitted rings. Matt can then plot their comings and goings and see how often they use the same boxes - and eventually will be able to see how far they have spread.
In the last two years tree sparrows have spread outward from the Downs - he has found them three kilometres south, one kilometre north and half a kilometre to the west. And recently - and quite by chance - he discovered a new colony in the Pewsey Vale - probably spread from one of his much cherished early colonies.
Its owners are very thrilled to have such important birds on their land and are keen to co-operate in providing nestboxes and in ringing
Tree sparrows are extinct in Dorset, Devon, Cornwall, Gloucestershire and Berkshire. One of the people Matt has trained to ring tree sparrows is starting a conservation scheme in Oxfordshire.
Matt believes there are about 225 pairs of tree sparrows living on the Marlborough Downs. Once it was said, half in jest, that 'Lapwing envy' had broken out among farmers with and without lapwing populations - now it seems we are into 'tree sparrow envy' between various farms and parts of North Wiltshire, with everyone keen to 'own' a tree sparrow village.
Matt's interest in tree sparrows began when he became Wiltshire Ornithological Society's (volunteer) Conservation Officer in 2000. Then there were about 30 pairs in North Wiltshire - not a sustainable population. Working on countryside stewardship schemes with interested farmers like David White, by 2010 there were about 140 pairs.
There is no doubt that this area and its current climate puts tree sparrows on the edge of survival: "It's possible to re-populate the Downs with tree sparrows if conditions are right - and they get a little help." Matt's work was beginning to seem on too small a scale to make the necessary difference. He started to look for an exit strategy.
Then David White and Robert Cooper and others formed a bid for a grant under the government's experimental Nature Improvement Areas scheme.
They won and became the only famer led group in the scheme - and conservation of birdlife on the Marlborough Downs took off in a big way: "The scheme's organiser, Jemma Batten, was amazing - she gets things done. We thought the birds on the downs lacked water - so they made more dew ponds."
"They left margins beside fields for wild flowers and they provided seed for winter feeding. The birds wanted corridors to move about the downs - so they planted corridors of trees and bushes - especially elder which attracts insects in the vital after harvest month of September. And they made tree sparrow 'villages' with protective trees, feeders and nesting boxes."
So 'a little help' for the tree sparrows became a major programme of help - now some farmers are even growing grains like millet to feed the birds in winter.
Farmers and landowners gave Matt what he calls 'extraordinary access' to their land to monitor and look after the tree sparrows. And along the way they were also helping other species - owls and all manner of other raptors, lapwings, corn buntings, wagtails and yellow hammers.
When the three years of government funding for the Nature Improvement Areas ended, the farmers decided to carry on by themselves. They are now the Marlborough Downs Space for Nature - they have a small grant from Natural England which covers the costs of the organiser.
Otherwise the farmers fund it themselves. Providing corn, nurturing the margins, putting up bird boxes - and arranging events to get people from the Marlborough area onto their downs.
Some people criticise the use of nesting boxes, but Matt points out that birds sometimes alternate between boxes and natural nests: "A box is just a hole for them to put their nest inside." And their interior design provides a deep and soft place for eggs and very young chicks.
Each box is numbered - Box Number One is on David White's land - and Matt knows exactly where they all are and checks them regularly. Ringing chicks must be done at the right moment. If the chicks are too big, they may get flustered and leave the nest before they are properly ready to fledge.
The day I travelled round the nestboxes with Matt was a good day for him and for the tree sparrows. He does have bad and depressing days.
Cold and wet days in May are bad for tree sparrows and much worse for their young. The insects needed to feed chicks vanish and get washed off trees by the rain. The death rate among hard-worked adults and chicks rises...
This is hard, time-consuming work for Matt Prior. But he loves the Downs. One of his 'best ever times' was a summer day when he was sitting on the ground ringing a brood, with a corn bunting and yellow hammer serenading him: "A very young leveret came up and gingerly started sniffing my boots - to see, perhaps, whether they might be edible."
The Royal Society for the Protection of Birds includes tree sparrows on its 'Red status' list of endangered birds - and publishes this background information on tree sparrows:
Smaller than a house sparrow and more active, with its tail almost permanently cocked. It has a chestnut brown head and nape (rather than grey), and white cheeks and collar with a contrasting black cheek spot.
They are shyer than house sparrows in the UK and are rarely associated with people... The UK tree sparrow population has suffered a severe decline, estimated at 93 per cent between 1970 and 2008.
However, recent Breeding Bird Survey data is encouraging, suggesting that numbers may have started to increase, albeit from a very low point. [Click on photos to enlarge them]